Dremel kit to chew and grind out the torn stuff, some acetone to prep the surface. White MarineTex (epoxy putty) to fill and rebuild
it, and practice a bit on some scrap if you're not sure how to use a proper putty knife or scraper to get a nice smooth finish on that. Then sand if needed to get a further smooth finish.
No, that won't perfectly match the gel coat but it will give you a strong repair that isn't hideous to look at.
You can get kits that will let you try to match the hull
color with gelcoat
, but that requires more practice and some artistic talent. To really disappear the damage, you'd wind
up repainting that entire side of the hull
. Which of course, is always an option.(G)